The GOP front-runner has faced accusations of sexism throughout the presidential race, with members of both parties denouncing remarks he has made about Fox News anchor Megyn Kelly and former GOP presidential candidate Carly Fiorina.

“That gives him a huge number of voters he has to make up from somewhere,” said American University political science professor Karen O’Connor. “And I don’t know where they will come from.”

Opposition to Trump among women also extends to the GOP. A recent NBC/Wall Street Journal poll found that 47 percent of Republican women could not see themselves supporting Trump, a number significantly higher than for any other GOP candidate.

“It further highlights the calamity that a Donald Trump nomination would be,” said Doug Heye, a former Republican National Committee aide who opposes Trump.

“While Republicans in the past have cried foul, rightly so, about Democrats talking about a war on women — Donald Trump has personally waged a war on women for decades.”

The latest controversy to stir talk of sexism flared Thursday, when Trump retweeted a picture of his wife, Melania Trump, and Cruz's wife. The comparison with Heidi Cruz was accompanied by the caption, "A picture is worth a thousand words."

The spouse rivalry started Tuesday night, after Cruz and Trump split primary victories in Arizona and Utah. In a tweet, the businessman threatened to “spill the beans” about Heidi Cruz.

Trump said the first tweet was in response an ad from an anti-Trump super-PAC that showed a nude photo of his wife from a GQ shoot. That ad had implored voters to choose Cruz.

Cruz says he had nothing to do with the ad, while Heidi Cruz added, “Most of the things Donald Trump says have no basis in reality.”

“Mitt Romney lost women 56 to 44 percent. Donald Trump is losing women 68 to 32 percent. The unfortunately reality for Donald Trump is if he wanted to be president, he should have run in 1904 — before women had the right to vote and before minorities had the right to vote.”

An ad released this month by Packer’s group featured women reading a slew of comments Trump had previously made about other women in front of the camera.

“It really doesn’t matter what you write as long as you have a young and beautiful piece of ass,” one woman said, quoting Trump.

“You have to treat them like shit,” said another woman in the ad, again quoting Trump.

Packer told The Hill that testing of the ad found more than 50 percent of viewers considered the ad to be new information, raising the possibility that such attacks from Democrats could lower his poll numbers even further.

She brushed aside any concerns that she might be making ads that could play into the hands of Democrats, arguing their attacks will be far worse.

“They are going to make Bain Capital look like Catholic Charities,” Packer said, referencing the attacks Democrats used about Romney’s private equity career.

“I have respect for my counterparts on the Democrat side, I’m not naive enough to think that if I don’t make the ad, they won’t come up with it. They’ll figure it out on their own. ... It’s such a target-rich environment.”

As Trump seeks to make inroads with more voters, he has a small handful of female backers who could act as surrogates in crucial battleground states — Sarah Palin and Jan Brewer in Arizona, Pam Bondi in Florida, where she is attorney general, and Rep. Renee Elmers (R) in her home state of North Carolina.

Neither Bondi nor Elmers returned requests through aides to comment.

If Trump ends up the Republican nominee, O’Connor doubts that he will be able to leave behind some of the comments he’s made in the primary process.

“These kinds of things really turn off women and they turn off women as mothers because they are telling their kids never to say those things,” she said.